Pizza Shack is better, but it is greasier (which probably makes it better)
Pie Works is more intimate than all the others - low lights/wait staff that gives a damn, and I would rank it second best pizza in the metro behind the Shack, followed by Sal and Mookies, then Soulshine rounds out the top four.
None of these are worth dropping $100 for a table though. Not sure any restaurant in Jackson is.